Space bar assembly

ABSTRACT

A manual keyboard unit having a number of regular manual keys of uniform &#39;&#39;&#39;&#39;touch&#39;&#39;&#39;&#39; or &#39;&#39;&#39;&#39;feel&#39;&#39;&#39;&#39; includes a commonly provided elongatgd manual input operator such as a space bar. The space bar is coupled to a motion equalizing or balancing assembly including a pair of supports coupled by a mechanism which imparts uniform movement to the elongated bar regardless of the point of manual actuation. A bias spring acting on the levers can balance the mass and friction of the equalizing assembly and the bar to give the space bar the desired &#39;&#39;&#39;&#39;touch&#39;&#39;&#39;&#39; or &#39;&#39;&#39;&#39;feel.

United States ?atent 1 Kerns, Jr.-

[ Nov. 13, 1973 SPACE BAR ASSEMBLY Mounting, J. N, Cassell, Vol. 9, No.12, May 1967, [75] Inventor: Frank F. Kerns, Jr., Samuels, Idaho page1773 [73] Assignee: Clare-Pendar Co., Post Falls, Idaho PrimaryExaminer-Ernest T. Wright, Jr. [22] Filed 1971 AttorneyMason,Kolehmainen, Rathburn & Wyss [21] Appl. No.1 130,681

[52] US. Cl. 197/82, 197/98 57 ST ACT [51] Int. Cl B4lj 19/00 [58] Fieldof Search; 197/82, 84 R, 84 A, A manual keyboard unit having a number ofregular 197/84 98 manual keys of uniform touch or feel includes acommonly provided elongatgd manual input operator [56] References cuedsuch as a space bar. The space bar is coupled to a mo- UNITED STATESPATENTS tion equalizing or balancing assembly including a pair 3,292,76112/1966 Erpel..'.... 197/82 of pp Coupled by a mechanism which imparts1,300,687 4/1919 Barr 197/82 uniform movement to the elongated barregardless of 968,985 8/1910 Robinson 197/98 X the point of manualactuation. A bias spring acting on 3, l/l972 Kosters 197/98 X the leverscan balance the mass and friction of the 134L115 1/1932 Gabe" 197/98 Uxequalizing assembly and the bar to give the space bar 3,457,368 7/1969Houcke 197/98 X the desired or OTHER PUBLICATIONS IBM TechnicalDisclosure Bulletin, Space Bar 26 Claims, 19 Drawing Figures 5 /66 /6 /01" 7 V w 33 a /6 4 40A 40 1 za z 405,54 e 50 -r4 (445 I465 1545 lll agPATENTEUNHV 13 1975 SHEET 10F 3 AlrmeA/ey PATENIEBImV 13 ms SHEET 2 OF 3UNN SPACE BAR ASSEMBLY This invention relates to a manual keyboard unitand, more particularly, to a new and improved space bar operatingassembly possessing a manual operating touch or feel consistent with theother manual keys in the keyboard.

Conventional keyboards and other manual data input units commonlyinclude, in addition to a number of regular keys or key buttons, one ormore elongated manual operators or keys such as the space bar. In thesekeyboards, particularly in electronic keyboard applications, it isdesirable that all of the keys, both the regular keys and the elongatedor large keys, possess the same touch or feel characteristics. In anelectronic keyboard, the regular keys commonly comprise a key actuatedswitch having a frame-supported housing with a key button carried on thefree end of the projecting key stem. The force resisting or overcome bythe manual operation of the regular key is the resilient or magnetic keystem return bias. However, with the elongated or enlarged keys, such asa space bar, the mass of the bar and its supporting means is greater,and this, considered alone or when added to the return bias of a switchactuated thereby, tends to give the elongated bar or key a substantiallydifferent feel or touch. Further, there is a tendency for elongated keysto cock and thus affect not only their touch but also the response ofthe switch operated thereby in dependence on the point of application ofthe manual operating force.

Accordingly, one object of the present invention is to provide a new andimproved keyboard assembly with uniform touch and feel throughout itskeys.

Anothe object is to provide a keyboard assembly including a new andimproved elongated key or bar for the keyboard possessing operatingcharacteristics consistent with the regular keys. 7

A further object is to provide a new and improved assembly of anelongated operator or key and an electric switch operated thereby.

A further object is to provide a new and improved assembly forcontrolling and equalizing movement of an elongated key such as a spacebar.

A further object is to provide a new and improved space bar assemblywith a motion equalizing assembly for controlling and guiding manuallyinduced movement of the bar in which the mass and friction of the barand equalizing assembly can be controlled, balanced, or compensated, andthe net force involved in the touch or feel of the space key can be madethe same as that of other keys in the keyboard unit.

In accordance with these and many other objects, an embodiment of theinvention comprises a keyboard unit of the type including a number ofelectric switch units whose housings are mounted on a supporting frameand from which project the key stems on the free end of which isdisposed a key actuating button. These switch units commonly includeresilient or magnetic means for biasing the switch and its operatingstem from an actuated to a normal or released position, and this biasingforce is the force overcome by manual operation. Such keyboard unitscommonly include, for example, an elongated key such as a space barwhich also controls the operation of an electric switch mounted on thesupporting frame. In accordance with the present invention, the spacebar is coupled to a motion equalizing mechanism carried on thesupporting frame which insures easy reciprocating movement of the barregardless of the point of application of pressure to the bar andmaintains the bar during its reciprocating movement in a predeterminedorientation with respect to the remaining keys or the supporting frame.

This equalizing mechanism can include a biasing means which balances orcompensates for the greater mass of the space bar and of the equalizingmechanism. Thus, the elongated space bar can be given the same touch orfeel as the remaining keys in the keyboard unit.

Many other objects and advantages of the present invention will becomeapparent from considering the following detailed description inconjunction with the drawing in which:

FIG. I is a front elevational view in partial section of an improvedspace bar assembly embodying the present invention which is shown in itsnormal position;

FIG. 2 is a sectional view taken along line 22 in FIG. 1;

FIG. 3 is a sectional view taken along line 33 in FIG. 1;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 1;

FIG. 5 is a sectional view similar to FIG. 1 and illustrates thekeyboard assembly in an actuated condition;

FIG. 6 is a front elevational view in partial section of an improvedspace bar assembly forming a second embodiment of the invention, theassembly being shown in its normal position;

FIG. 7 is a sectional view taken along line 7'7 in FIG. 6;

FIG. 8 is a sectional view taken along line 8-8 in FIG. 6;

FIG. 9 is a sectional view taken along line 9-9 in FIG. 6;

FIG. 10 is a sectional view taken along line l010 in FIG. 6;

FIG. 11 is a sectional view similar to FIG. 6 illustrating the space barassembly in an actuated position;

FIG. 12 is a fragmentary front elevational view in' partial sectionillustrating the space bar assembly in FIG. 6 with a different switchactuating assembly shown in normal position;

FIG. 13 is a sectional view taken along line l3-l3 in FIG. 12;

FIG. 14 is a fragmentary sectional view illustrating the space barassembly of FIG. 6 in its normal position and another embodiment of aswitch and controlling assembly;

FIG. 15 is a sectional view taken along line 15-15 in FIG. 14;

FIG. 16 is a sectional view taken along line 16-l6 in FIG. 14;

FIG. 17 is a perspective view of another embodiment of a motionequalizing assembly;

FIG. 18 is a perspective view of a further motion equalizing assembly;

FIG. 19 is a fragmentary sectional view of a keyboard unit or controlmeans with which the space bar assemblies can be used.

Referring now more specifically to FIG. 1 of the drawing, therein isillustrated an elongated key or space bar assembly which embodies thepresent invention and which is indicated generally as 10. The space barassembly 10 forms a part of a keyboard unit or control means 11 (FIG.19) having a supporting frame or structure 12 on which are mounted aplurality of input devices such as electric switches indicated generallyas 14. The electric switches 14 can be of any suitable and well knownconstruction and are mounted at spaced positions on the supporting frame12 to be manually actuated by conventional means such as a button 14Amounted on a key stem extending from the switch unit 14. The forcerequired to operate the regular switch unit 14 is that required toovercome the normally or commonly provided magnetic or resilient returnbias which acts to restore the key stem to a normal position when manualpressure is removed.

In accordance with the present invention, the space bar assemblyprovides the same operating characteristic, touch or feel as the regularkey buttons 14A and thus provides a keyboard unit 11 of uniformoperating characteristics. The space bar, operator, or operator memberassembly 10 includes an elongated space bar 16 provided with a motionequalizing or guiding mechanism or assembly which is indicated generallyas 18 and which is connected between the space bar 16 and the supportingstructure 12. The mechanism 18 in the illustrated embodiment insuresuniform reciprocating movement of the space bar 16 in a position ororientation generally parallel to the plane of the keyboard or itssupporting frame 12 regardless of the point of application of manualforce along the length of the space bar 16. In addition, the assembly 18includes biasing means that compensate or balance the mass and frictionof the space bar 16 and the mechanism 18. Accordingly, the net forceacting on the space bar 16 or resisting actuation of this space bar 16by the operator is nothing more than the return bias of the switch unit14, which force is identical to that of the remaining keys in thekeyboard assembly 11.

The construction of the electric switch or switch unit 14 can be of anysuitable well known construction using contact springs or sealed reedcontacts as shown in U.S. Pat. No. 3,462,719 or mercury-wetted contactsas shown in U.S. Pat. No. 3,497,837. In general, these switch unitsinclude, as with the switch unit 14 illustrated in FIG. 1, a housing 20secured in an aperture 21 on the supporting frame 12 and havingprojecting from a wall thereof a pair of output terminals 22. Projectingfrom the upper end of the switch unit 14 is an operating shaft or keystem 24 normally biased to an upward or released position by a biasingmeans shown schematically as a compression spring 26 interposed betweena fixed portion 20A of the housing 20 and a projection 24A on the keystem 24. In most of the keys in the keyboard assembly, a key button suchas those shown in the above-identified United States patents is mountedon the upper end of the key stem 24 to permit manual actuation.

In the illustrated switch unit 14 which forms a part of the space barassembly 10, a button 14A is not provided on the top of the key stem 24,and the upper edge of this key stem 24 abuts a resilient pad 28 securedto a block 16A projecting from the upper wall of the space bar 16 withinthe downwardly open cavity defined by an encircling skirt portion 16B ofthe space bar 16. When the space bar assembly 10 is in its normalposition, the switch unit 14 is released. When the space bar 16 ismanually depressed by the application of a manual force at any pointalong its length to the position shown in FIG. 5, the key stem 24 ismoved downwardly against the bias of the compression spring 26,

and the switch unit 14 is operated to either connect or disconnect theterminals 22 in dependence on the normally open or normally closedcharacter of the switch provided in the switch unit 14. When manualpressure is removed from the space bar 16, the assembly 10 is restoredto the normal position shown in FIG. 1, essentially or primarily byvirtue of the force of the biasing means or compression spring 26provided in the switch unit 14.

The mechanism or assembly 18 provides means for guiding and directingmovement of the space bar 16 relative to the supporting frame 12 whenthe space bar 16 is actuated, and, in the illustrated embodiment, soguides and controls movement of the space bar 16 that it remains in aposition or orientation extending generally parallel to the uppersurface of the supporting frame 12. A biasing means coupled to orassociated with the mechanism 18 balances or compensates the mass of thespace bar 16 and the mechanism 18 so that the touch or feel provided byactuation of the space bar 16 is the same as that obtained by operatingone of the regular keys in the keyboard unit 11.

To couple the space bar 16 to the mechanism or assembly 18, this spacebar 16 is provided with a pair of longitudinally spaced dependingmembers 16C in each of which is provided an opening 33 in which isreceived the upper shouldered end of one of a pair of supports orsupporting elements 34 and 36. The intermediate portions of thesupporting elements 34 and 36 are slidably received within slots orguide means 38 (FIGS. 3 and 5) in a bight or top wall 40A of a generallyU- shaped supporting frame 40 on which the mechanism or assembly 18 ismounted. The supporting frame 40 also includes a depending back wall 408(FIG. 5) and a somewhat tapered frontwall 40C. At its opposite ends, thelower edge of the back wall 40B is provided with a pair of forwardlyextending flanges or tabs 40D (FIG. 3) having slots or guide means 42 inwhich are slidably received the lower ends of the supporting elements 34and 36. The space bar 16, the mechanism or assembly 18, and the biasingmeans therefor form a complete subassembly carried solely on the frame40 to permit these components to be mounted on the supporting frame 12as an integral subassembly. To this end, the upper wall 40A of the frame40 includes a pair of projecting tabs 40E (FIGS. 1 and 5) at itsopposite ends which are secured by conventional fastening means 41 tothe adjacent wall portions of the supporting frame 12 with thesubassembly disposed in a corresponding opening 43 formed in thesupporting frame 12.

The supporting elements 34 and 36 are guided within slots 38 and 42which provide mounting means so that the space bar 16 is mounted forreciprocating rectilinear movement relative to both the subassemblyframe 40 and the supporting frame or structure 12 of the keyboard unit11. There is, however, the possibility that if the manual operatingforce is applied to either extremity of the space bar 16, one or theother of the supports or supporting'elemnts 34 or 36 would attempt tomove through a greater or lesser distance than the other of the supports34, 36 with the result that the supports 34, 36 would bind against theadjacent wall surfaces of the top wall 40A or the flange 40D with theresult that the space bar 16 would have to be forced to achieve adequatedepression to operate the switch unit 14. This in turn could result inerratic operation or damage to the switch unit 14 as well as frustratingthe desire to have the operating feel of the space bar 16 the same asthat of the other keys in the keyboard unit 11.

To prevent this and to insure movement of the space bar 16 in a parallelrelation to the keyboard unit 11 or to the supporting structure 12therefor, the mechanism 18 includes a pair of gear levers 44 and 46which are pivotally mounted between the front and back walls 40B, 40C ofthe subassembly frame 40 in positions generally aligned with each otherand disposed beneath the central portion of the space bar 16 by means ofa pair of shafts or pivot pins 48 which are carried on the walls 40B,40C and which pass through circular bossed portions 44A, 46A formed onthe gear levers 44, 46 intermediate their ends (FIG. 2). The innermostends of the gear levers 44 and 46 are provided with toothed or gearportions or segments 44B, 468 which mesh with each other. The outer freeends of the gear levers 44 and 46 are bifurcated to receive thesupporting elements 34 and 36 so that a pin 50 extending between thebifurcations on the levers 44 and 46 is disposed within a slot 34A, 36Ain the supporting elements 34 and 36. This pivotally couples the gearlevers 44 and 46 to the supporting elements 34 and 36 for the space bar16.

As set forth above, the mechanism 18 includes or there is coupled tothis mechanism and the space bar 16 a biasing means which balances,neutralizes, or compensates for the mass of the space bar 16 and themechanism 18 and the frictional forces thereof. In the illustratedembodiment, this biasing means includes a wire spring.54 (FIGS. 2, 4, 5)disposed between the back wall 408 and the gear levers 44 and 46. Thewire spring 54 includes a central portion 54C connecting a pair ofsingle convolution portions 54A received on and concentric with thebosses 44A and 46A on the gear levers 44 and 46. The free ends of thespring 54 are provided with offset portions 54B, each of which bearsagainst a lower edge of one of the gear levers 44 and 46. Thus, thespring or biasing means 54 tends to pivot the gear lever 44 in aclockwise direction about its pivot pin 48 (FIG. 5) and to pivot thegear lever 46 in a counterclockwise direction about its pivot pin 48.

In many applications, the assembly is mounted in the generally verticalor upright position shown in the drawing. This means that the weight ormass of the bar 16 and the coupled components of the mechanism 18 tendto move the bar 16 and coupled components downwardly. The biasing meansor spring 54 is designed to balance or equalize the downwardly directedforces arising from the mass of the stated components by providing acorresponding upwardly directed force. A perfect dynamic compensation,would leave the bias of the switch unit 14 as the net active force inthe system. However, it will be appreciated that the deflection of thefree ends of the spring 54 (FIGS. 1 and 5) will change somewhat theforces applied .to the system by the spring 54, and the spring 54 ischosen to equalize, as much as possible, the forces arising fromfriction and mass. In one assembly 10 constructed in accordance with thepresent invention, the bar 16 and mechanism 18, in the absence of theswitch unit 14, stabilize at a point between the normal position shownin FIG. 1 and the actuated position shown in FIG. 5. The'design of thespring 54 could change with change in the mounting position of theassembly 10, Le, a horizontal mounting, because the frictional and massconsiderations could change.

Referring now more specifically to the operation of the space barassembly 10, this assembly is normally in the normal position shown inFIG. 1 of the drawing. It is held in this position primarily by virtueof the biasing force of the compression spring 26 in the switch unit 14acting on the space bar 16 and the connected mechanism 18 through theprojection 16A, although a balancing force is applied to the system fromthe biasing means or spring 54. This normal position is determined byengagement of the lower surface of the flanges 40D by enlarged endportions 34B, 368 at the lower ends of the supporting elements 34, 36. Aresilient washer is disposed therebetween to cushion shocks.

Whenever a downwardly directed force is applied at any point along thespace bar 16, usually by digital pressure, the space bar 16 and thesupporting elements 34, 36 therefor begin to move downwardly againstprimarily the resilient bias of the compression spring 26 in the switchunit 14. As the supporting elements 34 and 36 move downwardly, the gearlevers 44 and 46 are pivoted about the pivot pins 48 in counterclockwiseand clockwise directions, respectively. If, for example, the force issupplied adjacent one or the other of the extremities of the elongatedspace bar 16 so that one or the other of the supports 34, 36 would tendto move downwardly more rapidly than the other, thus raising thepossibility of binding, the gear connection between the toothed or gearportions 44B, 46B on the two gear levers 44, 46 positively interlocksthe downward movement of the space bar supports 34, 36 so that they mustmove downwardly at the same speed. This avoids the possibility ofbinding these supports 34, 36 or skewing the position of the space bar16. Since the space bar 16 moves down without skewing or cocking, thekey stem 24 of the switching unit 14 is subjected to the expectedrectilinear movement, and the action of the switch unit 14 is positiveand proper. This also insures that the switch unit 14 is actuated withthe same degree of depression of the key stem 24 as the other keys inthe keyboard unit 11.

The downward movement of the space bar 16 controlled by the pivotingmovement of the gear levers 44 and 46 is terminated in the displacedposition shown in FIG. 5 by the engagement of the free ends of the gearlevers 44 and 46 with a pair of resilient pads 62 which encircle thesupporting elements 34 and 36 and which are interposed between the uppersurfaces of the flanges 40D and the lower surfaces of the bifurcatedends of the gear levers 44 and 46. When manual pressure is removed fromthe space bar 16, this space bar 16 moves upwardly to the normalposition shown in FIG. 1 and releases the actuated switch unit 14.

The force for moving the space bar 16 upwardly to its normal position isprovided primarily or essentially by the-biasing means or compressionspring 26 in the electric switch unit 14. The gear levers 44 and 46 onceagain equalize the reciprocating movement of the supports 34 and 36 sothat the space bar 16 moves upwardly, maintaining its desiredorientation with respect to the remaining keyboard units. The biasingmeans 54, in compensating for friction and the mass of the bar 16 andthe mechanism 18, insures that the primary power for moving thesecomponents is the bias of the switch unit 14. The upward movement isterminated when the resilient washers or elements 60 on the enlargedportions 34B, 36B of the bar supports 34, 36 engage the lower surfacesof the flanges 40D.

Accordingly, the space bar assembly 10 of the present invention providesmeans for insuring uniform predetermined movement of the space bar 16during its actuating and release movements and thus insures predictableand proper actuation of the switch unit 14. The gear levers 44 and 46prevent binding of the supports 34, 36, and the biasing means 54 incounterbalancing the mass and frictional force of the space bar 16 andthe mechanism 18 insures that actuation of the space bar 16 at any pointalong its length provides the same operating feel and touch as theactuation of a regular key in the keyboard unit 11. The use of the spacebar or elongated operator assembly 10 in keyboards of variousconstructions is facilitated by the present invention in which the bar16, the equalizing mechanism 18, and the biasing means 54 are formed asan integral subassembly carried by the supporting frame 40 which can beinserted or mounted as a unit in keyboard constructions of varioustypes.

Referring now more specifically to FIGS. 6-11 of the drawing, therein isillustrated a space bar assembly which is indicated generally as 70 andwhich embodies the present invention. The assembly 70 includes anelongated space bar operator, or operator member 72 similar to the spacebar 16 and mounted on a supporting frame 74 for movement between normaland displaced positions under the control of a motion equalizingmechanism or assembly indicated generally as 76 to control the selectiveoperation of a sealed switch 77. The assembly 70 is formed as asubassembly adapted to be mounted in the opening 43 in the supportingframe or base 12 and secured in position therein by suitable fasteners41. To facilitate the low cost fabrication of the assembly 70, the spacebar 72, the supporting structure or frame 74, and most of the componentsof the equalizing mechanism 76 can be formed as molded plastic parts.

To provide means for movably mounting the space bar 72 on the support74, a pair of identical space bar supports or supporting elements 78 areprovided having a generally cruciform cross section. The upper ends ofthe bar supports 78 are inserted into correspondingly formed openings orsockets 80 defined by two portions 72A projecting downwardly from thelower surface of the upper wall of the space bar 72 at points spacedfrom each other in its direction of elongation. The degree of insertionis limited by projections 78A (FIGS. 8 and 11) formed on the barsupports 78. To slidably mount the bar 72 on the supporting frame 74,the opposite ends of the frame 74 are provided with two closed portions74A, generally at the ends of the top wall 748, having generallycruciform shaped openings or guide means 82 (FIG. 10) therein in whichare slidably received intermediate portions of the bar supports 78. Anannular rubber gasket or damping member 83 is disposed on each of thebar supports 78 immediately beneath the projections 78A to cushion anyimpact between projections 78A on the bar supports 78 and the uppersurface .of the top wall 743 of the frame 74 when the space bar 72 isoperated to its displaced position shown in FIG. 11.

The motion equalizing assembly 76 is connected between the bar supports78 to insure uniform rectilinear sliding or reciprocating movement ofthe space bar 72 regardless of the point of application of operatingforce along its length. The assembly 76 includes a pair of identical andoppositely positioned levers 84 and 86 having hub portions 84A and 86Aadjacent their inner or first ends which are disposed between a backwall 74C and a front wall 74D of the frame 74. A pair of shafts or pins88 extending between the wall portions 74C and 74D and through the hubportions 84A and 86A pivotally mount the levers 84 and 86 on the frame74 with toothed or segmental gear portions or segments 84B and 868 attheir extreme inner ends in meshing engagement with each other.

To provide means for pivotally coupling the second or outer ends of thelevers 84 and 86 to the space bar supports 78, the outer ends of thesetwo levers 84, 86 are bifurcated to provide an opening 84C, 86C (FIGS. 7and 11) in which is received a flat portion 788 of the bar supports 78formed by interrupting two pairs of the ribs 78C or the cruciformsection of the bar supports 78. This affords a pivotal connectionbetween the levers 84, 86 and the bar supports 78.

To provide means for returning the assembly 76 and the space bar 72 to anormal position from a displaced position, a resilient biasing means isprovided acting on both of the levers 84 and 86. This biasing meansincludes a plunger 90 (FIGS. 9 and 11) having an upper cylindricalportion slidably mounted within a cylinder 92 formed by a cylindricalportion 74E extending downwardly from the bottom of the top wall 74B ofthe frame 74. A compression spring 94 is interposed between an enlargedlower head portion 90A on the piston 90 and the lower surface of the topwall 74B of the frame 74 surrounding the cylindrical projection 74E. Thecircular enlarged portion or head 90A on the plunger or piston 90 bearsagainst the upper edges of the levers 84, 86 immediately above the gearsegment portions 84B, 86B.

The compression spring 94 provides a bias sufficient to return the spacebar assembly 70 to the normal position shown in FIG. 6 determined byengagement of the levers 84, 86 with the portion 74A of the frame 74. Ifdesired, a resilient cushioning element can be interposed therebetween.Further and as set forth in detail above, the spring 94 can be sodesigned as to provide a resistance to movement of the space bar 72corresponding to the force required to actuate other keys in thekeyboard unit 11 so as to preserve a uniform touch throughout thekeyboard unit 11.

To provide means for mounting the sealed contact or switch unit 77 onthe frame 74 and to provide means for extending electrical connectionsthereto, a pair of electrically conductive terminals 96 and 98 areinserted in holes formed in or are molded into the frame 74 to lieimmediately adjacent the back wall 74C with the upper ends projectingabove the top surface of the top wall 748 of the frame 74. Theelectrically conductive terminals 77A of the sealed switch 77 aresecured as by soldering or welding to the upper ends of the terminals 96and 98. The lower ends of these terminals 96, 98 project below the spacebar assembly 70 to facilitate making electrical connections thereto.When mounted in this position by the terminals 96 and 98, the sealedswitch 77 extends in generally the same direction as the space bar 72and is completely covered thereby.

To provide means for operating the sealed switch 77, a permanent magnet100 (FIG. 9) is provided. This magnet 100 is carried in a holder 72Bwhich is formed integral with the space bar 72 and which is locatedwithin a cavity defined by the depending edges or skirt 72D of the spacebar 72. The holder 72B is secured to the remainder of the bar 72 by apair of spaced web portions 72C. The holder 72B and the permanent magnet100 are offset from the vertical plane encompassing the switch 77 topermit the magnet 100 to be moved to a position adjacent one side of theswitch 77. In a preferred embodiment, the magnet 100 is polarized in thedirection of its axial elongation so as to provide the most efficientoperating circuit for the magnetic elements of the switch 77, i.e.,these elements are disposed in a generally parallel relation with themagnet 100 when the space bar 72 is depressed.

When the space bar assembly 70 is actuated, the manual depressing forceis applied to the space bar 72 at any point along its length. As soon aseither one of the bar supports 78 moves downwardly, it pivots thecoupled lever 84, 86 in a counterclockwise or clockwise direction,respectively, about the shafts 88. Because of the coupling of the levers84, 86 through the meshed gear segments 84B, 868, any downward movementof one of the bar supports 78 results in a corresponding downwardmovement of the other bar support 78 so that the space bar 72 movesdownwardly toward the frame 12, 74 maintained in a generally parallelrelation thereto. Thus, any tendency for the space bar 72 and itssupports 78 to bind or become cocked is positively prevented.

During the downward movement of the space bar 72, the plunger '90 ismoved upwardly from the normal position shown in FIGS. 6 and 9 towardthe position shown in FIG. 11 in which the spring 94 is fullycompressed. The friction of the system coupled with the bias of thespring 94 can be arranged such that the touch of the space bar 72 is thesame'as other manually actuated keys in the keyboard assembly. As thespace bar '7 2 approaches the operated or displaced position shown inFIG. 11, the permanent'magnet 100 is moved immediately adjacent the sidewall of the sealed switch 77, and the magnetic field from the permanentmagnet 100 shifts the magnetic contact elements of the sealed switchunit 77 into engagement to complete a conductive circuit between theterminals 96 and 98 in the usual manner. Because of the fact that theassembly 76 maintains the space bar 72 in its desired relationshiprelative to the supporting frame 74 on which the switch 77 is mounted,the switch 77 will be operated uniformly on each stroke of the space bar72 and with the expected operating characteristics.

When manual pressure is removed from the space bar 72, the compressionspring 94 bearing on the piston or plunger 90 forces the ends of thelevers 84 and 86 carrying the gear segments 84B, 86B downwardly to pivotthe levers 84 and 86 in clockwise and counterclockwise directions,respectively. Through the pivotal connection of these levers 84, 86 tothe bar supports 78, the bar supports 78 are moved upwardly to returnthe space bar 72 to the normal position shown in FIG. 6 and to removethe magnetic field of the permanent magnet 100 from proximity to thesealed switch 77 so that this switch 77 releases to interrupt theconductive circuit between the terminals 96 and 98.

Referring now more specifically to FIGS. 12 and 13 of the drawing,therein is illustrated a space bar assembly 110 providing anotherembodiment of the invention. The space bar assembly 110 issubstantially-identical to the space bar assembly 70 except for thelocation of and means for effecting operation of a sealed switch unit112. In the space bar assembly 110, a pair of electrical terminals 114and 116 are molded into or inserted into openings in the top wall 748 ofthe frame 74 immediately adjacent the front wall 74D to dependdownwardly therefrom adjacent the lever 84. Two terminals 112A and 1123extending from opposite ends of the sealed switch unit 112 are securedas by soldering or welding to the electrically conductive terminals 114and 116, respectively, in such a position that the switch capsule 112normally is disposed in an inclined position beneath the lever 84 and atone side thereof. This position is also such that the sealed switch 112is disposed adjacent the lever 84 when this lever 84 is moved to itsactuated position.

To provide permanent magnet means for selectively controlling theoperation of the switch 112, a permanent magnet 118 is secured by eitherfriction fit or by an adhesive in an opening 119 formed intermediate thelength of the lever 84. The permanent magnet 1 18 is so disposed withinthe opening 119 on the lever 84 that when the lever 84 is moved to itsdisplaced position, the magnet 118 is disposed adjacent and extendssubstantially in a parallel relation to the inclined switch 112 as shownin dot-and-dash outline in FIG. 12.

When the space bar assembly is operated by depression of the space bar72 in the manner described above, the space bar supports 78 movedownwardly and the levers 84 and 86 are pivoted in counterclockwise andclockwise directions, respectively. When the lever 84 is moved to itsextreme counterclockwise position determined by the engagement of theO-ring or resilient bumper 83 with the top wall 748 of the frame 74, thepermanent magnet 118 is disposed parallel to and immediately contiguousthe sealed switch 112 with the length of the permanent magnet 118overlying the gap between the spaced magnetic and electricallyconductive reeds of the switch 112. This moves these reeds intoengagement and completes an electrical circuit between the terminals 114and 116 through the switch 112.

When the space bar 72 is released, the compression spring 94 pivots thelevers 84 and 86 in clockwise and counterclockwise directions,respectively, to restore the space bar 72 from the operated or displacedposition shown in' dotand-dashoutline to the normal position illustratedin FIG. 12'. This moves the permanent magnet 118 away from the sealedswitch 112 and permits this switch 112 to open. If desired, anadditional reed switch and additional supporting terminals similar tothe terminals 114 and 116 can be disposed adjacent the lever 86 or onthe opposite side of the lever 84. An additional permanent magnetsimilar to the magnet 1 18 is provided for these levers 84, 86 toincrease the number of contacts controlled by the actuation of the spacebar 72.

FIGS. 14-16 illustrate a space bar assembly 120 which forms a furtherembodiment of the invention. The space bar assembly 120 is substantiallyidentical to the space bar assembly 70 with the exception of theposition of, the mounting for, and the means for operating a sealedswitch 122. The sealed switch 122 is disposed within a supportinghousing 124 which is secured to and depends from the lower surface ofthe upper wall 748 of the frame 74. The housing 124 is mounted spacedfrom and extending generally parallel to the adjacent one of the barsupports 78, and two terminals 122A and 122B for the switch 122 projectbelow the lower wall of the housing 124 (FIG. 16) to facilitate makingelectrical connections to the switch 122.

To provide means for controlling the selective operation of the switch122, the space bar assembly 120 in cludes a permanent magnet 126disposed within a carrier 128 having a lower circular portion 128A intowhich the lower end of a bar support 78 is received and secured theretoeither frictionally or by the use of adhesive. The holder or carrier 128also includes a generallycylindrical magnet holding portion 128B securedto the portion 128A by an intervening web portion. The permanent magnet126 is generally cylindrical in configuration, is axially polarized, andis inserted into the open top of the cylindrical holder portion 128B.The holder 128 has an opening or slot along the side adjacent the switch122. The permanent magnet 126 extends in generally the same direction asthe switch 122 and is normally disposed (FIG. 14) in a position spacedsufficiently above the gap between the reeds in the switch 122 that itis not effective to cause operation of the switch 122.

However, when the space bar 72 is depressed to move the bar supports 78downwardly, the holder 128 carried on the bar support 78 movesrectilinearly downwardly so that the permanent magnet 126 overlaps thegap between the reeds in the switch 122 and applies a flux fieldsufficient to close these contacts, thereby completing an electricallyconductive circuit between the switch terminals 122A and 122B. Becauseof the rectilinear movement of the space bar support 78 and thus thecarrier 128 carried thereon, the permanent magnet 126 is disposedparallel to the sealed switch 122 and provides the most efficientmagnetic circuit for effecting operation of the switch 122. When manualpressure is removed from the space bar 72, the compression spring 94effects the above-described pivotal movement of the levers 84 and 86,and the bar supports 78 move upwardly so that the magnet 126 is nolonger disposed in proximity to the gap between the magnetic reeds inthe switch 122. This releases the switch 122.

FIG. 17 of the drawing illustrates a motion or movement equalizinglinkage indicated generally as 130 which can be used in place of theillustrated mechanism 76 described above. To insure equalized ornonbinding movement of the space bar 72, the linkage or mechanism 130includes a pair of levers 132 and 134 provided with hub portions 132A,134A adjacent their inner or first ends through which extend pivotalmounting shafts 136 whose opposite free ends are adapted to be receivedwithin openings formed in the front and back walls 74D, 74C of the frame74. The inner ends of the levers 132 and 134 are coupled for conjointmovement by providing a bifurcated portion 132B in the lever 132 intowhich fits or is received a tongue or projecting portion 134B formed onthe lever 134. A resilient biasing means such as the plunger 90 and thecompression spring 94 adapted to bear on the upper surface of thebifurcated portion 132B provides a return bias for the linkage 130.

The outer or second ends of the levers 132 and 134 are each providedwith a tongue or projecting portion 132C, 134C which are received withingenerally circular openings formed in a pair of bar supports 138. Thebar supports 138 are similar to the bar supports 78 and are providedwith a cruciform section 138A at their upper ends to permit the barsupports 138 to be coupled to the space bar 72. The remaining portion ofthe bar supports 138 is generally rectangular or square in section andis adapted to be slidably received within a corresponding opening at theends 74A of the frame 74 to slidably mount the bar supports 138 on theframe 74. The configuration of the opening formed in the end portion 74Aof the frame 74 must be changed to one corresponding to that of the barsupports 138 to permit this installation. Alternatively, the cruciformsection of the top portions 138A can be extended downwardly intoproximity to the openings receiving the tongues 132C, 134C, and thelinkage can be directly mounted on the frame 74 shown and describedabove.

The operation of the linkage 130 is the same as that of the mechanism 76described above. In response to depression of the space bar 72, the barsupports 138 are moved downwardly against the bias provided by thecompression spring 94 so that the levers 132 and 134 are pivoted aboutthe shafts 136 in counterclockwise and clockwise directions,respectively. The coupling of the levers 132, 134 by the portions 1328,1348 equalizes the movement of the bar supports 138 to insure nonbindingmovement of the space bar 72 in a position maintained generally parallelto the frame 12. The various switch and switch controlling assembliesillustrated above in FIGS. 1, 6, 12, and 14 can be used in a space barassembly using the linkage 130.

FIG. 13 illustrates a further embodiment of a linkage 140 useful in thespace bar assembly to provide a motion equalizing mechanism or assembly.The linkage 140 includes an integral flexible bar effectively dividedinto a first pivotally mounted lever 142 and a second pivotally mountedlever 144 by a generally V-shaped notch 146 which provides a flexibleand integrally formed pivotal connection indicated generally as 148between the levers 142 and 144. Each of the levers 142, 144 includes ahub or bossed portion 142A, 144A through which extends a pivotalmounting shaft 149, the outer or opposite ends of which are receivedwithin openings formed in the front and back walls 74D, 74C in the frame74. The shafts 149 can be molded integral with the levers 142, 144 orprovided by separately inserted pins.

The linkage 140 also includes a pair of bar supports 150 of arectangular section similar to the bar supports 138 and each providedwith a cruciform top portion 150A for receiving and mounting the spacebar 72. The intermediate portions of the bar supports 150 are slidablyreceived within correspondingly formed openings in the end portions 74Aof the frame 74. The bar supports 150 are integrally connected to thelevers 142 and 144 by a section of reduced thickness 1503 which providesa flexible, integral, pivotal connection between the bar supports 150and the levers 142, 144. In the space bar assembly using the linkage140, the switch and switch controlling arrangement can be of any of thetypes illustrated and described in detail above.

Further, although a separate biasing means such as the plunger 90 andthe compression spring 94 can be provided bearing on the levers 142, 144at the flexible joint indicated at 148, it is possible to construct alinkage 140 in which the deflection of the plastic material provides thereturn bias. More specifically, the plastic material forming the pivotalconnections 148 and 1508 can also be chosen to have a sufficienttendency to return to the normal state shown in FIG. 18 to provide thereturn bias.

When the linkage 140 is incorporated into a space bar assembly 70 andthe space bar 72 is depressed, the supports 150 are moved downwardly. Assoon as one of these supports 150 begins to move downwardly, theconnected one of the levers 142, 144 is pivoted in a counterclockwise orclockwise direction, respectively, and is effective through the pivotalconnection 148 to cause a corresponding movement of the other of thelevers 142, 144 In this manner, both of the bar supports 150 are moveddownwardly at the same rate to prevent binding of the space bar 72during actuation. The downward movement of the space bar supports 150 issubstantially rectilinear and ispermitted even though these bar supports150 are integrally connected to the levers 142, 144 because of thepivotal connections formed at 150B. When pressure is removed from thespace bar 72, either the separate biasing means described above or theinherent tendency of the distorted plastic material in the areas 148 and150B causesthe levers 142 and 144 to be pivoted about the shafts 149 inclockwise and counterclockwise directions, respectively, to move the barsupports 150 upwardly to their normal position.

Although the present invention has been described with reference to anumber of illustrative embodiments thereof, it should be understood thatnumerous other modifications and embodiments falling within the spiritand scope of the principles of this invention will be apparent to thoseskilled in the art.

What is claimed and desired to be secured by Letters Patent of theUnited States is:

1. An elongated operator assembly for use with key input unitscomprising an elongated operator member movable in a given plane betweennormal and displaced positions,

a supporting frame,

means mounting the operator member on the frame for reciprocating andrectilinear movement in said plane,

a mechanism including a pair of levers pivotally mounted on the framefor movement in said plane and underlying the operator member with eachlever coupled to the operator member at a different spaced point, saidlevers being coupled together to control the path of movement of theoperator member in said plane between said normal and displacedpositions of the operator member,

and biasing means coupled to the mechanism and providing a biasing forcesubstantially balancing the weight of the operator member and mechanism.

2. A bar operator assembly for use in a keyboard assembly of the typeusing a number of individual manual key actuated switches having a givenkey return biasing force comprising an elongated bar having a mass andmovable between normal and displaced positions,

a supporting structure,

a mechanism having a mass and carried on the supporting structure andcoupled to the bar at points spaced from each other in the direction ofelongation of the bar, said mechanism including a pair of supportingelements secured to the bar at said spaced points and slidably engagingthe supporting structure for mounting the bar on the supportingstructure for rectilinear reciprocating movement, said mechanism alsoincluding movement equalizing means underlying the bar and coupling theelements to each other to maintain said bar in a given orientationduring movement between said normal and displaced positions of the bar,

biasing means coupled between the supporting structure and the coupledmechanism and bar for balancing the mass and friction of the mechanismand the bar,

and an electric switch means coupled to the bar for actuation thereby toan operated position, said electric switch means having a bias means forreturning the electric switch means from the operated position of theelectric switch means and for returning the coupled bar and mechanism toa normal position.

'3. The bar operator assembly set forth in claim 2 including guide meansfor guiding the supporting elements for reciprocating movement,

and in which the movement equalizing means includes a pair of leverspivotally mounted on the supporting structure intermediate their ends,pivotally coupled to the different ones of the supporting elements atone end, and having meshed toothed segments at their other ends.

4. The bar operator assembly set forth in claim 3 in which the biasingmeans is coupled to the pair of levers. 5. The bar operator assembly setforth in claim 2 in which the electric switch means includes anoperator, and including means mounting the electric switch means withthe operator for the electric switch means disposed to engage theelongated bar adjacent one end of the bar. 6. The bar operator assemblyset forth in claim 5 including means mounting the mechanism generallybeneath a center portion of the elongated barv 7. The bar operatorassembly set forth in claim 2 in which the coupled bar, mechanism, andbiasing means form a single connected assembly, and means are providedfor detachably mounting the assembly of the bar, mechanism, and biasingmeans on the supporting structure. 8. A bar operator assembly for use ina key input unit comprising an elongated bar movable in oppositedirections between normal and displaced positions, a supportingstructure, and a mechanism including a pair of levers each having firstand second ends and each pivoted on the supporting structureintermediate their first and second ends, said mechanism having firstcoupling means coupling the first ends of the levers for conjointmovement, said mechanism also including second coupling means couplingthe second ends of the levers to the elongated bar at points spaced fromeach other in the direction of elongation of the bar, the first andsecond coupling means in said mechanism effecting oppositely directedpivotal movement of the pair of levers as the elongated bar moves ineither of said opposite directions between said normal and displacedpositions of the elongated bar to maintain a given orientation of theelongated bar during movement of the elongated bar between said normaland displaced positions of the elongated bar.

9. The bar operator assembly set forth in claim 8 in which the secondcoupling means includes bar supports coupled to the elongated bar atpoints spaced in the direction of elongation of the bar and mounted forreciprocating movement on the supporting structure, said second couplingmeans also including pivot means providing a pivotal connection betweenthe second ends of the levers and the bar supports.

10. The bar operator assembly set forth in claim 9 in which the pivotmeans includes a flexible integral connection between the bar supportsand levers.

11. The bar operator assembly set forth in claim 9 in which the pivotmeans includes cooperating projecting portions and recesses on thesecond ends of the levers and the bar supports.

12. The bar operator assembly set forth in claim 8 in which the firstcoupling means includes cooperating projections and recesses on thefirst ends of the levers.

13. The bar operator assembly set forth in claim 12 in which thecooperating projections and recesses include meshing gear segments onthe first ends of both of the levers.

14. The bar operator assembly set forth in claim 12 in which thecooperating projections and recesses include a single projection on thefirst end of one of the levers and a single recess on the first end ofthe other lever.

15. The bar operator assembly set forth in claim 8 in which the firstcoupling means includes an integral, flexible connection between thefirst ends of the levers.

16. The bar operator assembly set forth in claim 8 including resilientmeans acting on the levers adjacent the first ends of the levers.

17. The bar operator assembly set forth in claim 8 including switchmeans operated by movement of said elongated bar to the displacedposition of the elongated bar.

18. A bar operator assembly for use in a key input unit comprising anelongated bar movable in opposite directions between normal anddisplaced positions,

a supporting structure,

a mechanism including a pair of levers each having first and second endsand pivoted on the supporting structure intermediate their first andsecond ends, said mechanism having first coupling means coupling thefirst ends of the levers for conjoint movement, said mechanism alsoincluding second coupling means coupling the second ends of the leversto the elongated bar at points spaced from each other in the directionof elongation of the bar, the first and second coupling means in saidmechanism effecting oppositely directed pivotal movement of the pair oflevers along paths of movement as the elongated bar moves in either ofsaid opposite directions between said normal and displaced positions ofthe elongated bar to maintain a given orientation of the elongated barduring movement of the elongated bar between said normal and displacedpositions of the elongated bar,

a magnetically controlled switch,

permanent magnet means for controlling the operation of the switch,

and means mounting the switch and the permanent magnet means adjacenteach other for movement relative to each other so that movement of theelongated bar controls operation of the switch.

19. The bar operator assembly set forth in claim 18 in which the switchis mounted in a fixed position on the supporting structure.

20. The bar operator assembly set forth in claim 19 in which thepermanent magnet means is mounted on the elongated bar.

21. The bar operator assembly set forth in claim 20 in which the switchis mounted beneath the permanent magnet means in a position with theelongated bar overlying the switch.

22. The bar operator assembly set forth in claim 19 in which thepermanent magnet means is mounted on one of the levers.

23. The bar operator assembly set forth in claim 22 including mountingmeans mounting the switch adjacent the path of movement of the one ofthe levers carrying the permanent magnet means.

24. The bar operator assembly set forth in claim 23 in which thesupporting structure includes an insulating portion,

and the mounting means includes at least one electrically conductiveterminal carried on the insulating portion and extending adjacent thepath of movement of the lever carrying the permanent magnet means, theswitch being connected to the terminal.

25. The bar operator assembly set forth in claim 19 in which the secondcoupling means includes a pair of bar supports connected to the bar atpoints spaced in the direction of elongation of the bar,

and the permanent magnet means is mounted on one of the bar supports.

26. A bar operator assembly for use in a key input unit comprising asupporting structure,

an elongated bar,

a pair of supporting elements connected to spaced points on theelongated bar and slidably mounted on the supporting structure to mountthe elongated bar on the supporting structure for reciprocatingrectilinear movement, and

a mechanism including a pair of levers pivotally mounted on thesupporting structure underlying the elongated bar for equalizingmovement of the elongated bar, said pair of levers extending in thedirection of elongation of the bar and having spaced first and secondends, said levers having their first ends coupled together and theirsecond ends individually coupled to different ones of the supportingelements.

1. An elongated operator assembly for use with key input unitscomprising an elongated operator member movable in a given plane betweennormal and displaced positions, a supporting frame, means mounting theoperator member on the frame for reciprocating and rectilinear movementin said plane, a mechanism including a pair of levers pivotally mountedon the frame for movement in said plane and underlying the operatormember with each lever coupled to the operator member at a differentspaced point, said levers being coupled together to control the path ofmovement of the operator member in said plane between said normal anddisplaced positions of the operator member, and biasing means coupled tothe mechanism and providing a biasing force substantially balancing theweight of the operator member and mechanism.
 2. A bar operator assemblyfor use in a keyboard assembly of the type using a number of individualmanual key actuated switches having a given key return biasing forcecomprising an elongated bar having a mass and movable between normal anddisplaced positions, a supporting structure, a mechanism having a massand carried on the supporting structure and coupled to the bar at pointsspaced from each other in the direction of elongation of the bar, saidmechanism including a pair of supporting elements secured to the bar atsaid spaced points and slidably engaging the supporting structure formounting the bar on the supporting structure for rectilinearreciprocating movement, said mechanism also including movementequalizing means underlying the bar and coupling the elements to eachother to maintain said bar in a given orientation during movementbetween said normal and displaced positions of the bar, biasing meanscoupled between the supporting structure and the coupled mechanism andbar for balancing the mass and friction of the mechanism and the bar,and an electric switch means coupled to the bar for actuation thereby toan operated position, said electric switch means having a bias means forreturning the electric switch means from the operated position of theelectric switch means and for returning the coupled bar and mechanism toa normal position.
 3. The bar operator assembly set forth in claim 2including guide means for guiding the supporting elements forreciprocating movement, and in which the movement equalizing meansincludes a pair of levers pivotally mounted on the supporting structureintermediate their ends, pivotally coupled to the different ones of thesupporting elements at one end, and having meshed toothed segments attheir other ends.
 4. The bar operator assembly set forth in claim 3 inwhich the biasing means is coupled to the pair of levers.
 5. The baroperator assembly set forth in claim 2 in which the electric switchmeans includes an operator, and including means mounting the electricswitch means with the operator for the electric switch means disposed toengage the elongated bar adjacent one end of the bar.
 6. The baroperator assembly set forth in claim 5 including means mounting themechanism generally beneath a center portion of the elongated bar. 7.The bar operator assembly set forth in claim 2 in which the coupled bar,mechanism, and biasing means form a single connected assembly, and meansare provided for detachably mounting the assembly of the bAr, mechanism,and biasing means on the supporting structure.
 8. A bar operatorassembly for use in a key input unit comprising an elongated bar movablein opposite directions between normal and displaced positions, asupporting structure, and a mechanism including a pair of levers eachhaving first and second ends and each pivoted on the supportingstructure intermediate their first and second ends, said mechanismhaving first coupling means coupling the first ends of the levers forconjoint movement, said mechanism also including second coupling meanscoupling the second ends of the levers to the elongated bar at pointsspaced from each other in the direction of elongation of the bar, thefirst and second coupling means in said mechanism effecting oppositelydirected pivotal movement of the pair of levers as the elongated barmoves in either of said opposite directions between said normal anddisplaced positions of the elongated bar to maintain a given orientationof the elongated bar during movement of the elongated bar between saidnormal and displaced positions of the elongated bar.
 9. The bar operatorassembly set forth in claim 8 in which the second coupling meansincludes bar supports coupled to the elongated bar at points spaced inthe direction of elongation of the bar and mounted for reciprocatingmovement on the supporting structure, said second coupling means alsoincluding pivot means providing a pivotal connection between the secondends of the levers and the bar supports.
 10. The bar operator assemblyset forth in claim 9 in which the pivot means includes a flexibleintegral connection between the bar supports and levers.
 11. The baroperator assembly set forth in claim 9 in which the pivot means includescooperating projecting portions and recesses on the second ends of thelevers and the bar supports.
 12. The bar operator assembly set forth inclaim 8 in which the first coupling means includes cooperatingprojections and recesses on the first ends of the levers.
 13. The baroperator assembly set forth in claim 12 in which the cooperatingprojections and recesses include meshing gear segments on the first endsof both of the levers.
 14. The bar operator assembly set forth in claim12 in which the cooperating projections and recesses include a singleprojection on the first end of one of the levers and a single recess onthe first end of the other lever.
 15. The bar operator assembly setforth in claim 8 in which the first coupling means includes an integral,flexible connection between the first ends of the levers.
 16. The baroperator assembly set forth in claim 8 including resilient means actingon the levers adjacent the first ends of the levers.
 17. The baroperator assembly set forth in claim 8 including switch means operatedby movement of said elongated bar to the displaced position of theelongated bar.
 18. A bar operator assembly for use in a key input unitcomprising an elongated bar movable in opposite directions betweennormal and displaced positions, a supporting structure, a mechanismincluding a pair of levers each having first and second ends and pivotedon the supporting structure intermediate their first and second ends,said mechanism having first coupling means coupling the first ends ofthe levers for conjoint movement, said mechanism also including secondcoupling means coupling the second ends of the levers to the elongatedbar at points spaced from each other in the direction of elongation ofthe bar, the first and second coupling means in said mechanism effectingoppositely directed pivotal movement of the pair of levers along pathsof movement as the elongated bar moves in either of said oppositedirections between said normal and displaced positions of the elongatedbar to maintain a given orientation of the elongated bar during movementof the elongated bar between said normal and displaced positions of theelongated Bar, a magnetically controlled switch, permanent magnet meansfor controlling the operation of the switch, and means mounting theswitch and the permanent magnet means adjacent each other for movementrelative to each other so that movement of the elongated bar controlsoperation of the switch.
 19. The bar operator assembly set forth inclaim 18 in which the switch is mounted in a fixed position on thesupporting structure.
 20. The bar operator assembly set forth in claim19 in which the permanent magnet means is mounted on the elongated bar.21. The bar operator assembly set forth in claim 20 in which the switchis mounted beneath the permanent magnet means in a position with theelongated bar overlying the switch.
 22. The bar operator assembly setforth in claim 19 in which the permanent magnet means is mounted on oneof the levers.
 23. The bar operator assembly set forth in claim 22including mounting means mounting the switch adjacent the path ofmovement of the one of the levers carrying the permanent magnet means.24. The bar operator assembly set forth in claim 23 in which thesupporting structure includes an insulating portion, and the mountingmeans includes at least one electrically conductive terminal carried onthe insulating portion and extending adjacent the path of movement ofthe lever carrying the permanent magnet means, the switch beingconnected to the terminal.
 25. The bar operator assembly set forth inclaim 19 in which the second coupling means includes a pair of barsupports connected to the bar at points spaced in the direction ofelongation of the bar, and the permanent magnet means is mounted on oneof the bar supports.
 26. A bar operator assembly for use in a key inputunit comprising a supporting structure, an elongated bar, a pair ofsupporting elements connected to spaced points on the elongated bar andslidably mounted on the supporting structure to mount the elongated baron the supporting structure for reciprocating rectilinear movement, anda mechanism including a pair of levers pivotally mounted on thesupporting structure underlying the elongated bar for equalizingmovement of the elongated bar, said pair of levers extending in thedirection of elongation of the bar and having spaced first and secondends, said levers having their first ends coupled together and theirsecond ends individually coupled to different ones of the supportingelements.